1qcc

<table><tr><td colspan='2'>[[1qcc]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Leido Leido]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QCC OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1QCC FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CIT:CITRIC+ACID'>CIT</scene></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1qcc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qcc OCA], [http://pdbe.org/1qcc PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1qcc RCSB], [http://www.ebi.ac.uk/pdbsum/1qcc PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1qcc ProSAT]</span></td></tr>

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

The enzyme adenine phosphoribosyltransferase (APRT) functions to salvage adenine by converting it to adenosine-5-monophosphate (AMP). APRT deficiency in humans is a well characterized inborn error of metabolism, and APRT may contribute to the indispensable nutritional role of purine salvage in protozoan parasites, all of which lack de novo purine biosynthesis. We determined crystal structures for APRT from Leishmania donovani in complex with the substrate adenine, the product AMP, and sulfate and citrate ions that appear to mimic the binding of phosphate moieties. Overall, these structures are very similar to each other, although the adenine and AMP complexes show different patterns of hydrogen-bonding to the base, and the active site pocket opens slightly to accommodate the larger AMP ligand. Whereas AMP adopts a single conformation, adenine binds in two mutually exclusive orientations: one orientation providing adenine-specific hydrogen bonds and the other apparently positioning adenine for the enzymatic reaction. The core of APRT is similar to that of other phosphoribosyltransferases, although the adenine-binding domain is quite different. A C-terminal extension, unique to Leishmania APRTs, extends an extensive dimer interface by wrapping around the partner molecule. The active site involves residues from both subunits of the dimer, indicating that dimerization is essential for catalysis.

Crystal structures of adenine phosphoribosyltransferase from Leishmania donovani.,Phillips CL, Ullman B, Brennan RG, Hill CP EMBO J. 1999 Jul 1;18(13):3533-45. PMID:10393170<ref>PMID:10393170</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

</div>

<div class="pdbe-citations 1qcc" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Leido]]

[[Category: Brennan, R G]]

[[Category: Hill, C P]]

[[Category: Phillips, C L]]

[[Category: Ullman, B]]

[[Category: Transferase]]